Cache plays main role in magento. Magento has two levels of cache.
- A Fast level
- A Slow level
There are various type of caching are available like FileSystem , APC, Memcache and Redis cache.
Cache and fullpage caches are maintained in filesystem, for storage we can use SSD Hardisk can be used, which we can read the files faster. This is only useful to smail Buisness with low traffic.
Alternative PHP Cache is free opcode cache for PHP. It is optimize the PHP intermediate code
APC PHP Module will not speed up the module, instead of that its eliminates the delay caused by Magento PHP .tags are not supported. Slow level cache is needed
Memcache is a high performance , distributed memory object caching system, generic in nature, this is the very fast cache backend without tags..
Tags are not supported. Slow level cache is needed
redis cache store advanced key-store with full cache tag support.
Very Fast cache backend with fully tag support , No Slow level cache is needed.
Depends on buisness we can choose cache mechanism, suppose if it is small buisness , then we can have the APC with second level cache as filesystem.
Redis cache will be the perfect solutions for multiple server environment and large buisness.